First parser attempt.

ooi/occi/parser/headers.py

@@ -0,0 +1,79 @@
+# -*- coding: utf-8 -*-
+
+# Copyright 2015 Spanish National Research Council
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import shlex
+
+#from ooi import exception
+
+
+def _lexize(s, separator, ignore_whitespace=False):
+    lex = shlex.shlex(instream=s, posix=True)
+    lex.commenters = ""
+    if ignore_whitespace:
+        lex.whitespace = separator
+    else:
+        lex.whitespace += separator
+    lex.whitespace_split = True
+    return list(lex)
+
+
+class HeaderParser(object):
+    # TODO(enolfc): invalid input will crash this function!
+    def parse(self, headers):
+        obj = {
+            "kind": None,
+            "mixins": [],
+            "attributes": {},
+        }
+        for ctg in _lexize(headers["Category"],
+                           separator=",",
+                           ignore_whitespace=True):
+            ll = _lexize(ctg, ";")
+            d = {"term": ll[0]}  # assumes 1st element => term's value
+            d.update(dict([i.split('=') for i in ll[1:]]))
+            ctg_class = d.get("class", None)
+            ctg_type = '%(scheme)s%(term)s' % d
+            if ctg_class == "kind":
+                if obj.get("kind") is not None:
+                    # TODO(enolfc): use a better exception
+                    #raise exception.HeaderValidation()
+                    raise Exception("Two kinds in an object??")
+                obj["kind"] = ctg_type
+            elif ctg_class == "mixin":
+                obj["mixins"].append(ctg_type)
+        for attr in _lexize(headers["X-OCCI-Attribute"],
+                            separator=",",
+                            ignore_whitespace=True):
+            n, v = attr.split('=', 1)
+            ns = n.strip().split('.')
+            d = obj["attributes"]
+            for s in ns[:-1]:
+                try:
+                    d = d[s]
+                except KeyError:
+                    d[s] = {}
+                    d = d[s]
+            d[ns[-1]] = v
+        print obj
+
+
+#hdrs = {
+#    "Category": 'compute;scheme="http://schemas.ogf.org/occi/infrastructure#";class="kind",foo;scheme="http://schemas.openstack.org/template/resource#";class="mixin",bar;scheme="http://schemas.openstack.org/template/os#";class="mixin",user_data;scheme="http://schemas.openstack.org/compute/instance#";class="mixin"',
+#    "X-OCCI-Attribute": 'occi.core.id="1234", occi.core.size=12, occi.core.bool="true", occi.core.shitty="1234 234"'
+#}
+#
+#parser = HeaderParser()
+#parser.parse(hdrs)